Analogs of parathyroid hormone

ABSTRACT

The present invention is directed to peptide analogues of fragment of parathyroid hormone (PTH) or parathyroid hormone-related protein (PTHrP), a method of using said analogues alone or in combination with a bisphosphonate or calcitonin to treat osteoporosis and pharmaceutical compositions comprising said analogues alone or in combination with a bisphosphonate or calcitonin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of both U.S. application Ser. No. 08/779,768 filed Jan. 7, 1997, now issued as U.S. Pat. No. 5,969,095, and Ser. No. 09/341,217, filed Nov. 22, 1999, now abandoned, which is the national phase application of International Application No. PCT/US97/22498, filed Dec. 8, 1997, which is a continuation-in-part of U.S. application Ser. No. 08/813,534, filed Mar. 7, 1997, now issued as U.S. Pat. No. 5,955,574, which is a continuation-in-part of U.S. application Ser. No. 08/779,768, filed Jan. 7, 1997, now issued as U.S. Pat. No. 5,969,095, which is a continuation-in-part of U.S. application Ser. No. 08/626,186, filed Mar. 29, 1996, now issued as U.S. Pat. No. 5,723,577, which claims the benefit of priority of U.S. Application No. 60/003,305, filed Sep. 6, 1995 and U.S. Application No. 60/001,105, filed Jul. 13, 1995.

BACKGROUND OF THE INVENTION

Parathyroid hormone (“PTH”) is a polypeptide produced by the parathyroid glands. The mature circulating form of the hormone is comprised of 84 amino acid residues. The biological action of PTH can be reproduced by a peptide fragment of its N-terminus (e.g. amino acid residues 1 through 34). Parathyroid hormone-related protein (“PTHrP”) is a 139 to 173 amino acid-protein with N-terminal homology to PTH. PTHrP shares many of the biological effects of PTH including binding to a common PTH/PTHrP receptor. Tregear, et al., Endocrinol., 93:1349 (1983). PTH peptides from many different sources, e.g., human, bovine, rat, chicken, have been characterized. Nissenson, et al., Receptor, 3:193 (1993).

PTH has been shown to both improve bone mass and quality. Dempster, et al., Endocrine Rev., 14:690 (1993); and Riggs, Amer. J. Med., 91 (Suppl. 5B):37S (1991). The anabolic effect of intermittently administered PTH has been observed in osteoporotic men and women either with or without concurrent antiresorptive therapy. Slovik, et al., J. Bone Miner. Res., 1:377 (1986); Reeve, et al., Br. Med. J., 301:314 (1990); and Hesch, R-D., et al., Calcif. Tissue Int'l, 44:176 (1989).

SUMMARY OF THE INVENTION

In one aspect, the invention features a peptide of the formula (I),

wherein

A₁ is Ser, Ala, or Dap;

A₃ is Ser, Thr, or Aib;

A₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Acc, Phe or p-X-Phe, in which X is OH, a halogen, or CH₃;

A₇ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Acc, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₈ is Met, Nva, Leu, Val, Ile, Cha, Acc, or Nle;

A₁₁ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Acc, Phe or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₂ is Gly, Acc, or Aib;

A₁₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Acc, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₆ is Ser, Asn, Ala, or Aib;

A₁₇ is Ser, Thr, or Aib;

A₁₈ is Met, Nva, Leu, Val, Ile, Nle, Acc, Cha, or Aib;

A₁₉ is Glu or Aib;

A₂₁ is Val, Acc, Cha, or Met;

A₂₂ is Acc or Glu;

A₂₃ is Trp, Acc, or Cha;

A₂₄ is Leu, Acc, or Cha;

A₂₇ is Lys, Aib, Leu, hArg, Gln, Acc, or Cha;

A₂₈ is Leu, Acc, or Cha;

A₂₉ is Gln, Acc, or Aib;

A₃₀ is Asp or Lys;

A₃₁ is Val, Leu, Nle, Acc, Cha, or deleted;

A₃₂ is His or deleted;

A₃₃ is Asn or deleted;

A₃₄ is Phe, Tyr, Amp, Aib, or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxy-phenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H, or CONH₂; provided that at least one of A₅, A₇, A₈, A₁₁, A₁₂, A₁₅, A₁₈, A₂₁, A₂₂, A₂₃, A₂₄, A₂₇, A₂₈, A₂₉, and A₃₁ is Acc; or a pharmaceutically acceptable salt thereof.

A preferred embodiment of the immediately foregoing peptide is where A₃ is Ser; A₅ is Ile or Acc; A₇ is Leu, Acc, or Cha; A₈ is Acc, Met, Nva, Leu, Val, Ile, or Nle; A₁₁ is Leu, Acc, or Cha; A₁₂ is Acc or Gly; A₁₅ is Leu, Acc, or Cha; A₁₆ is Asn or Aib; A₁₇ is Ser or Aib; A₁₈ is Acc, Met, or Nle; A₂₁ is Val or Acc; A₂₇ is Lys, hArg, Acc, or Cha; A₃₁ is Val, Leu, Nle, Acc, or Cha; A₃₂ is His; A₃₃ is Asn; A₃₄ is Phe, Tyr, Amp, or Aib; or a pharmaceutically acceptable salt thereof.

A preferred embodiment of the immediately foregoing peptide, designated Group B, is where A₅ is Ile or Ahc; A₇ is Leu, Ahc, or Cha; A₈ is Ahc, Met, or Nle; A₁₁ is Leu, Ahc, or Cha; A₁₂ is Ahc or Gly; A₁₅ is Leu, Ahc, or Cha; A₁₈ is Met or Ahc; A₂₁ is Val or Ahc; A₂₂ is Glu or Ahc; A₂₃ is Trp, Ahc, or Cha; A₂₄ is Leu, Ahc, or Cha; A₂₇ is Lys, hArg, Ahc, or Cha; A₂₈ is Leu, Ahc, or Cha; A₂₉ is Gln, Ahc, or Aib; A₃₁ is Val, Leu, Nle, Ahc, or Cha; R₁ is H; R₂ is H; and R₃ is NH₂; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group B is where at least one of A₇, A₁₁, A₁₅, A₂₃, A₂₄, A₂₇, A₂₈, or A₃₁ is Cha.

Another preferred group of peptides of Group B is where at least one of A₁₆, A₁₇, A₁₉, A₂₉, or A₃₄ is Aib.

Preferred peptides of formula (I) are [Ahc^(7,11)]hPTH(1-34)NH₂; [Ahc^(7,11), Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂; [Ahc¹¹]hPTH(1-34)NH₂; [Ahc^(7,11,15)]hPTH(1-34)NH₂; [Ahc⁷]hPTH(1-34)NH₂; [Ahc²³]hPTH(1-34)NH₂; [Ahc²⁴]hPTH(1-34)NH₂; [Nle^(8,18), Ahc²⁷]hPTH(1-34)NH₂; [Ahc²⁸]hPTH(1-34)NH₂; [Ahc³¹]hPTH(1-34)NH₂; [Ahc^(24,28,31)]hPTH(1-34)NH₂; [Ahc^(24,28,31), Lys³⁰]hPTH(1-34)NH₂; [Ahc^(28,31)]hPTH(1-34)NH₂; [Ahc¹⁵]hPTH(1-34)NH₂; [Ahc^(24,27), Aib²⁹, Lys³⁰]hPTH(1-34)NH₂; [Ahc^(24,27), Aib²⁹, Lys³⁰, Leu³¹]hPTH(1-34)NH₂; [Ahc⁵]hPTH(1-34)NH₂; [Ahc¹²]hPTH(1-34)NH₂; [Ahc²⁷]hPTH(1-34)NH₂; [Ahc²⁹]hPTH(1-34)NH₂; [Ahc^(24,27)]hPTH(1-34)NH₂; [Ahc^(24,27), Aib²⁹]hPTH(1-34)NH₂; [Ahc²⁴, Aib²⁹]hPTH(1-34)NH₂; [Ahc²⁷, Aib²⁹]hPTH(1-34)NH₂; [Ahc¹⁸]hPTH(1-34)NH₂; [Ahc⁸]hPTH(1-34)NH₂; [Ahc^(18,27), Aib²⁹]hPTH(1-34)NH₂; or [Ahc^(18,24,27), Aib²⁹]hPTH(1-34)NH₂; [Ahc²², Leu²⁷, Aib²⁹]hPTH(1-34)NH₂; [Ahc²⁴, Leu²⁷, Aib²⁹]hPTH(1-34)NH₂; [Ahc²²]hPTH(1-34)NH₂; and [Acc²², Aib²⁹]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

The invention also features peptides of the following formulae: [Cha^(22,23), Glu²⁵, Lys^(26,30), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib²⁹, Nle³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,30,31), Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,30,31), Lys²⁶]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Nle³⁰]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Cha¹⁵, Glu^(22,25), Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys²⁶, Leu^(28,31), Aib²⁹, Nle³⁰]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu²⁵, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Nle³⁰]hPTHrP(1-34)NH₂; [Cha^(7,11,15)]hPTHrP(1-34)NH₂; [Cha^(7,8,15)]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Aib^(25,29), Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Aib^(25,29), Lys²⁶, Leu²⁸]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Aib^(25,29), Lys²⁶]hPTHrP(1-34)NH₂; [Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys²⁶, Leu^(28,31), Aib²⁹, Nle³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Aib²⁹, Leu³¹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib^(29,30)]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Aib^(26,29), Lys³⁰)]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; or [Leu²⁷, Aib²⁹]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

The following are examples of the peptides of the invention covered by the above formula: [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,25), Ahc²³, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Ahc²⁴, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Aib^(25,29), Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; [Acc²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,31), Lys^(26,30), Ahc²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Ahc²³, Glu²⁵, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24,27), Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Ahc^(24,27), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc^(24,27), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(18,24,27), Glu²², Cha²³, Lys^(25,26), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc²⁴, Lyc^(25,26), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Ahc²⁷, Aib²⁹, Nle³⁰]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25), Leu^(23,28,31), Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Cha¹⁵, Glu^(22,25), Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Ahc²³, Glu²⁵, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Ahc²³, Aib^(25,29), Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys^(26,30), Ahc²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Ahc²⁴, Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Ahc^(24,27), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Ahc^(24,27), Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24,27), Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Aib^(25,29), Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; [Ahc^(22,27), Leu^(23,28,31), Aib^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc^(24,27), Lys^(25,26,30), Aib²⁹]hPTHrP 1-34)NH₂; [Glu²², Leu^(23,28), Ahc^(24,27), Lys^(25,26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc^(24,27), Lys^(25,26,30), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Ahc^(24,27), Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc^(24,27), Lys^(25,26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc^(24,27), Lys^(25,26), Aib²⁹, ]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Ahc^(24,27), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc^(24,26), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc^(24,27), Lys^(25,26), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Lys^(25,26), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Lys^(25,26), Acc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Lys^(25,26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Lys^(25,28,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Cha²³, Ahc²⁴, Lys^(25,26), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib²⁹, Ahc³⁰]hPTHrP(1-34)NH₂; [Aib^(22,29), Leu^(23,28,31), Glu²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha²², Ahc²³, Glu^(25,29), Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Acc²⁴, Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,31), Glu^(25,29), Lys^(26,30), Ahc²⁸]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28), Glu^(25,29), Lys^(26,30), Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,29), Ahc²³, Aib²⁵, Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Aib²⁵, Lys^(26,30), Glu²⁹]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Ahc²⁴, Aib²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,31), Aib²⁵, Lys^(26,30), Ahc²⁸]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28), Aib²⁵, Lys^(26,30), Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Ahc²⁷, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Ahc²⁴, Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28), Glu^(25,29), Lys^(26,30,31)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28), Lys^(26,31), Ahc³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28), Lys^(26,30,31), Ahc²⁷]hPTHrP(1-34)NH₂; [Ahc²², Cha²³, Glu²⁵, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc²², Cha²³, Lys^(25,26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc²², Cha²³, Lys^(25,26), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28), Arg²⁵, Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24), Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24),Leu^(23,28,31), Lys^(25,26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24), Leu^(23,28,31), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24), Leu^(23,28), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc^(22,24), Leu^(23,28), Arg²⁵, Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc²⁴, Lys^(25,26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc²⁴, Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Ahc²⁴, Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc²⁴, Arg²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc²⁴, Arg²⁵, Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Ahc²⁴, Arg²⁵, Lys²⁶, Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Ahc²³, Aib^(25,29), Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Glu²², Ahc²³, Aib^(25,29), Lys²⁶, Leu²⁸]hPTHrP(1-34)NH₂; [Glu²², Ahc^(23,31), Aib^(25,29), Lys²⁶, Leu²⁸]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Aib^(25,29), Lys^(26,30), Ahc³¹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28), Aib^(25,29), Lys²⁶, Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28), Acc^(24,31), Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; or [Glu²², Leu^(23,28), Ahc^(24,31), Lys^(25,26), Aib²⁹]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Ahc²⁴, Aib^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

In another aspect, the invention relates to peptide variants of PTH(1-34) of the following generic formula:

wherein

A₁ is Ser, Ala, or Dap;

A₃ is Ser, Thr, or Aib;

A₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe, in which X is OH, a halogen, or CH₃;

A₇ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₈ is Met, Nva, Leu, Val, Ile, Cha, or Nle;

A₁₁ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₂ is Gly or Aib;

A₁₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₆ is Ser, Asn, Ala, or Aib;

A₁₇ is Ser, Thr, or Aib;

A₁₈ is Met, Nva, Leu, Val, Ile, Nle, Cha, or Aib;

A₁₉ is Glu or Aib;

A₂₁ is Val, Cha, or Met;

A₂₃ is Trp or Cha;

A₂₄ is Leu or Cha;

A₂₇ is Lys, Aib, Leu, hArg, Gln, or Cha;

A₂₈ is Leu or Cha;

A₃₀ is Asp or Lys;

A₃₁ is Val, Nle, Cha, or deleted;

A₃₂ is His or deleted;

A₃₃ is Asn or deleted;

A₃₄ is Phe, Tyr, Amp, Aib, or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxy-phenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H, or CONH₂;

provided that (i) at least one of A₅, A₇, A₈, A₁₁, A₁₅, A₁₈, A₂₁, A₂₃, A₂₄, A₂₇, a₂₈, and A₃₁ is Cha, or at least one of A₃, A₁₂, A₁₆, A₁₇, A₁₈, A₁₉, and A₃₄ is Aib; or that (ii) at least A₁ is Dap, A₇ is β-Nal, Trp, Pal, Phe, or p-X-Phe, A₁₅ is β-Nal, Trp, Pal, Phe, or p-X-Phe, A₂₇ is hArg, or A₃₁ is Nle; or a pharmaceutically acceptable salt thereof.

In another aspect, the invention relates to peptide variants of PTH(1-34) of the following formula (II):

wherein

A₁ is Ser, Ala, or Dap;

A₃ is Ser, Thr, or Aib;

A₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe, in which X is OH, a halogen, or CH₃;

A₇ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₈ is Met, Nva, Leu, Val, Ile, Cha, or Nle;

A₁₁ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₂ is Gly or Aib;

A₁₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₆ is Ser, Asn, Ala, or Aib;

A₁₇ is Ser, Thr, or Aib;

A₁₈ is Met, Nva, Leu, Val, Ile, Nle, Cha, or Aib;

A₁₉ is Glu or Aib;

A₂₁ is Val, Cha, or Met;

A₂₃ is Trp or Cha;

A₂₄ is Leu or Cha;

A₂₇ is Lys, Aib, Leu, hArg, Gln, or Cha;

A₂₈ is Leu or Cha;

A₃₀ is Asp or Lys;

A₃₁ is Val, Nle, Cha, or deleted;

A₃₂ is His or deleted;

A₃₃ is Asn or deleted;

A₃₄ is Phe, Tyr, Amp, Aib, or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxy-phenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H, or CONH₂;

provided that (i) at least one of A₅, A₇, A₈, A₁₁, A₁₅, A₁₈, A₂₁, A₂₃, A₂₄, A₂₇, A₂₈, and A₃₁ is Cha, or at least one of A₃, A₁₂, A₁₆, A₁₇, A₁₈, A₁₉, and A₃₄ is Aib; and the peptide is not [Aib¹², Tyr³⁴]hPTH(1-34)NH₂. or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of formula (II), designated Group (i) is where at least one of A₇, A₁₁, A₁₅, A₂₃, A₂₄, A₂₇, A₂₈, and A₃₁ is Cha; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (i), designated Group (ii), is where A₃ is Ser; A₅ is Ile; A₇ is Leu or Cha; A₈ is Met, Nva, Leu, Val, Ile, or Nle; A₁₁ is Leu or Cha; A₁₂ is Gly; A₁₅ is Leu or Cha; A₁₆ is Asn or Aib; A₁₇ is Ser; A₁₈ is Met or Nle; A₂₁ is Val; A₂₇ is Lys, hArg, or Cha; A₃₂ is His; A₃₁ is Val, Nle, or Cha; A₃₃ is Asn; A₃₄ is Phe, Tyr, Amp, or Aib; R₁ is H; R₂ is H; and R₃ is NH₂; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (ii), designated Group (iii), is where at least one of A₇ and A₁₁ is Cha; or a pharmaceutically acceptable salt thereof.

Preferred peptides of Group (iii) are [Cha^(7,11)]hPTH(1-34)NH₂, [Cha^(7,11), Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂; [Cha¹¹]hPTH(1-34)NH₂; [Cha^(7,11,15)]hPTH(1-34)NH₂; and [Cha⁷]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

Another preferred group of peptides of Group (ii), designated Group (iv), is where at least one of A₁₅, A₂₃, A₂₄, A₂₇, A₂₈, and A₃₁ is Cha; or a pharmaceutically acceptable salt thereof.

Preferred peptides of Group (iv) are [Cha²³]hPTH(1-34)NH₂, [Cha²⁴]hPTH(1-34)NH₂, [Nle^(8,18), Cha²⁷]hPTH(1-34)NH₂, [Cha²⁸]hPTH(1-34)NH₂, [Cha³¹]hPTH(1-34)NH₂, [Cha^(24,28,31)]hPTH(1-34)NH₂; [Cha^(24,28,31), Lys³⁰]hPTH(1-34)NH₂; [Cha^(28,31)]hPTH(1-34)NH₂; and [Cha¹⁵]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

Another preferred group of peptides of formula (II), designated Group (v), is where at least one of A₃, A₁₂, A₁₆, A₁₇, A₁₈, A₁₉, and A₃₄ is Aib; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (v), designated Group (vi), is where A₃ is Ser or Aib; A₅ is Ile; A₇ is Leu or Cha; A₈ is Met, Nva, Leu, Val, Ile, or Nle; A₁₁ is Leu or Cha; A₁₅ is Leu or Cha; A₁₆ is Asn or Aib; A₁₈ is Met, Aib, or Nle; A₂₁ is Val; A₂₇ is Lys, Aib, Leu, hArg, or Cha; A₃₁ is Val, Nle, or Cha; A₃₂ is His; A₃₃ is Asn; A₃₄ is Phe, Tyr, Amp, or Aib; R₁ is H; R₂ is H; and R₃ is NH₂; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (vi), designated Group (vii), is where at least one of A₃, A₁₂, A₁₆, A₁₇, A₁₉, and A₃₄ is Aib; or a pharmaceutically acceptable salt thereof.

Preferred peptides of Group (vii) are [Aib¹⁶]hPTH(1-34)NH₂, [Aib¹⁹]hPTH(1-34)NH₂, [Aib³⁴]hPTH(1-34)NH₂; [Aib^(16,19)]hPTH(1-34)NH₂; [Aib³]hPTH(1-34)NH₂; [Aib¹⁷]hPTH(1-34)NH₂; and [Aib¹²]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

Another preferred group of peptides of formula (II), designated Group (viii), is where at least one of A₇, A₁₁, A₁₅, A₂₃, A₂₄, A₂₇, A₂₈, and A₃₁ is Cha and at least of A₃, A₁₂, A₁₆, A₁₇, A₁₈, A₁₉, and A₃₄ is Aib; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (viii), designated Group (ix), is where A₃ is Ser or Aib; A₅ is Ile; A₇ is Leu or Cha; A₈ is Met, Nva, Leu, Val, Ile, or Nle; A₁₁ is Leu or Cha; A₁₅ is Leu or Cha; A₁₆ is Asn or Aib; A₁₈ is Met, Aib, or Nle; A₂₁ is Val; A₂₇ is Lys, Aib, Leu, hArg, or Cha; A₃₁ is Val, Nle, or Cha; A₃₂ is His; A₃₃ is Asn; A₃₄ is Phe, Tyr, Amp, or Aib; R₁ is H; R₂ is H; and R₃ is NH₂; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of Group (ix), designated Group (x), is where at least one of A₇ and A₁₁ is Cha and at least one of A₁₆, A₁₉, and A₃₄ is Aib; or a pharmaceutically acceptable salt thereof.

Preferred peptides of Group (x) are [Cha^(7,11), Nle^(8,18), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂, [Cha^(7,11), Nle^(8,18,31), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂; [Cha^(7,11), Aib¹⁹]hPTH(1-34)NH₂; [Cha^(7,11), Aib¹⁶]hPTH(1-34)NH₂; [Cha^(7,11), Nle^(8,18), Aib³⁴]hPTH(1-34)NH₂; or [Cha^(7,11), Aib¹⁹, Lys³⁰]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

Another preferred group of peptides of Group (ix), designated Group (xi), is where at least one of A₂₄, A₂₈, and A₃₁ is Cha and at least one of A₁₆ and A₁₇ is Aib; or a pharmaceutically acceptable salt thereof.

Preferred peptides of Group (xi) are [Cha²⁸, Nle^(8,18), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂, and [Cha²⁸, Aib^(16,19)]PTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

In another aspect, the present invention is directed to a peptide of the formula (III):

wherein

A₃ is Ser, Thr, or Aib;

A₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe, in which X is OH, a halogen, or CH₃;

A₇ is Leu, Ile, Nle, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is H, OH, a halogen, or CH₃;

A₈ is Met, Nva, Leu, Val, Ile, Cha, or Nle;

A₁₁ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₂ is Gly or Aib;

A₁₅ is Leu, Nle, Ile, Cha, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₁₆ is Ser, Asn, Ala, or Aib;

A₁₇ is Ser, Thr, or Aib;

A₁₈ is Met, Nva, Leu, Val, Ile, Nle, Cha, or Aib;

A₁₉ is Glu or Aib;

A₂₁ is Val, Cha, or Met;

A₂₃ is Trp or Cha;

A₂₄ is Leu or Cha;

A₂₇ is Lys, Aib, Leu, hArg, Gln, or Cha;

A₂₈ is Leu or Cha;

A₃₀ is Asp or Lys;

A₃₁ is Val, Nle, Cha, or deleted;

A₃₂ is His or deleted;

A₃₃ is Asn or deleted;

A₃₄ is Phe, Tyr, Amp, Aib, or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxy-phenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl;

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H, or CONH₂;

provided that at least A₁ is Dap, A₇ is β-Nal, Trp, Pal, Phe, or p-X-Phe; A₁₅ is β-Nal, Trp, Pal, Phe, or p-X-Phe, A₂₇ is hArg, or A₃₁ is Nle; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of formula (III) is where A₁ is Ser, Gly, or Dap; A₃ is Ser or Aib; A₈ is Met, Nva, Leu, Val, Ile, or Nle; A₁₆ is Asn or Aib; A₁₈ is Met, Aib, or Nle; A₂₁ is Val; A₂₇ is Lys, Aib, Leu, hArg, or Cha; A₃₁ is Val, Nle, or Cha; A₃₂ is His; A₃₃ is Asn; A₃₄ is Phe, Tyr, Amp, or Aib; R₁ is H; R₂ is H; and R₃ is NH₂; or a pharmaceutically acceptable salt thereof.

Preferred peptides of the immediately foregoing peptides are [Nle³¹]hPTH(1-34)NH₂, [hArg²⁷]hPTH(1-34)NH₂, and [Dap¹, Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂; or a pharmaceutically acceptable salt thereof.

In another aspect, the present invention is directed to a peptide of the formula (IV):

wherein

A₁ is Ala, Ser, or Dap;

A₃ is Ser or Aib;

A₅ is His, Ile, or Cha;

A₇ is Leu, Cha, Nle, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₈ is Leu, Met, or Cha;

A₁₀ is Asp or Asn;

A₁₁ is Lys, Leu, Cha, Phe, or β-Nal;

A₁₂ is Gly or Aib;

A₁₄ is Ser or His;

A₁₅ is Ile, or Cha;

A₁₆ is Gln or Aib;

A₁₇ is Asp or Aib;

A₁₈ is Leu, Aib, or Cha;

A₁₉ is Arg or Aib;

A₂₂ is Phe, Glu, Aib, or Cha;

A₂₃ is Phe, Leu, Lys, or Cha;

A₂₄ is Leu, Lys, or Cha;

A₂₅ is His, Aib, or Glu;

A₂₆ is His, Aib, or Lys;

A₂₇ is Leu, Lys, or Cha;

A₂₈ is Ile, Leu, Lys, or Cha;

A₂₉ is Ala, Glu, or Aib;

A₃₀ is Glu, Cha, Aib, or Lys;

A₃₁ is Ile, Leu, Cha, Lys, or deleted;

A₃₂ is His or deleted;

A₃₃ is Thr or deleted;

A₃₄ is Ala or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkanyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂, hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H or CONH₂;

provided that at least one of A₅, A₇, A₈, A₁₁, A₁₅, A,₁₈, A₂₂, A₂₃, A₂₄, A₂₇, A₂₈, A₃₀, or A₃₁ is Cha, or at least one of A₃, A₁₂, A,₁₆, A₁₇, A₁₈, A₁₉, A₂₂, A₂₅, A₂₆, A₂₉, A₃₀, or A₃₄ is Aib; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of formula (IV) is where A₂₂ is Phe or Cha; A₂₃ is Phe or Cha; A₂₅ is His; A₂₆ is His; A₂₇ is Leu or Cha; A₂₈ is Ile or Cha; A₂₉ is Ala; A₃₀ is Glu or Lys; A₃₁ is Ile or Cha; A₃₂ is His; A₃₃ is Thr; and A₃₄ is Ala; or a pharmaceutically acceptable salt thereof. Two preferred groups of peptides of the immediately foregoing group of peptides is where at least one of A₇ and A₁₁ is Cha; or where at least one of A₁₆ or A₁₉ is Aib; or a pharmaceutically acceptable salt thereof.

Another preferred group of peptides of formula (IV), is where A₂₂ is Glu, Aib, or Cha; A₂₃ is Leu, Lys, or Cha; A₂₅ is Aib or Glu; A₂₆ is Aib or Lys; A₂₈ is Leu, Lys, or Cha; A₂₉ is Glu or Aib; A₃₀ is Cha, Aib, or Lys; A₃₁ is Leu, Cha, or Lys; A₃₂ is His; A₃₃ is Thr; and A₃₄ is Ala; or a pharmaceutically acceptable salt thereof. Two preferred groups of peptides of the immediately foregoing group of peptides is where at least one of A₇ and A₁₁ is Cha; or where at least one of A₁₆ or A₁₉ is Aib; or a pharmaceutically acceptable salt thereof.

In another aspect, this invention is directed to a peptide of the formula (V):

wherein

A₁ is Ala, Ser or Dap;

A₃ is Ser or Aib;

A₅ is His, Ile or Cha;

A₇ is Leu, Cha, Nle, β-Nal, Trp, Pal, Phe, or p-X-Phe in which X is OH, a halogen or CH₃;

A₈ is Leu, Met or Cha;

A₁₀ is Asp or Asn;

A₁₁ is Lys, Leu, Cha, Phe or β-Nal;

A₁₂ is Gly or Aib;

A₁₄ is Ser or His;

A₁₅ is Ile or Cha;

A₁₆ is Gln or Aib;

A₁₇ is Asp or Aib;

A₁₈ is Leu, Aib or Cha;

A₁₉ is Arg or Aib;

A₂₂ is Phe, Glu, Aib, Acc or Cha;

A₂₃ is Phe, Leu, Lys, Acc or Cha;

A₂₄ is Leu, Lys, Acc or Cha;

A₂₅ is His, Aib or Glu;

A₂₆ is His, Aib or Lys;

A₂₇ is Leu, Lys, Acc or Cha;

A₂₈ is Ile, Leu, Lys, Acc or Cha;

A₂₉ is Ala, Glu or Aib;

A₃₀ is Glu, Cha, Aib, Acc or Lys;

A₃₁ is Ile, Leu, Cha, Lys, Acc or deleted;

A₃₂ is His or deleted;

A₃₃ is Thr or deleted;

A₃₄ is Ala or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkanyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂, hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H or CONH₂;

provided that at least one of A₂₃, A₂₄, A₂₇, A₂₈, or A₃₁ is Lys; or a pharmaceutically acceptable salt thereof.

A preferred group of peptides of formula (V) is where A₂₂ is Glu, Aib, Acc, or Cha; A₂₃ is Leu, Lys, Acc, or Cha; A₂₅ is Aib or Glu; A₂₆ is Aib or Lys; A₂₈ is Leu, Lys, Acc, or Cha; A₂₉ is Glu or Aib; A₃₀ is Cha, Aib, Acc, or Lys; A₃₁ is Leu, Cha, Acc, or Lys; A₃₂ is His; A₃₃ is Thr; and A₃₄ is Ala; or a pharmaceutically acceptable salt thereof. Two preferred groups of peptides of the immediately foregoing group of peptides is where at least one of A₇ and A₁₁ is Cha; or where at least one of A₁₆ or A₁₉ is Aib; or a pharmaceutically acceptable salt thereof.

The following are examples of peptides of this invention as encompassed by formula (II): [Cha⁷]hPTH(1-34)NH₂; [Cha¹¹]hPTH(1-34)NH₂; [Cha¹⁵]hPTH(1-34)NH₂; [Cha^(7,11)]hPTH(1-34)NH₂; [Cha^(7,11)Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂; [Cha²³]hPTH(1-34)NH₂; [Cha²⁴]hPTH(1-34)NH₂; [Nle^(8,18), Cha²⁷]hPTH(1-34)NH₂; [Cha²⁸]hPTH(1-34)NH₂; [Cha³¹]hPTH(1-34)NH₂; [Cha²⁷]hPTH(1-34)NH₂; [Cha^(27,29)]hPTH(1-34)NH₂; [Cha²⁸]bPTH(1-34)NH₂; [Cha²⁸]rPTH(1-34)NH₂; [Cha^(24,28,31)]hPTH(1-34)NH₂; [Aib¹⁶]hPTH(1-34)NH₂; [Aib¹⁹]hPTH(1-34)NH₂; [Aib³⁴]hPTH(1-34)NH₂; [Aib^(16,19)]hPTH(1-34)NH₂; [Aib^(16,19,34)]bPTH(1-34)NH₂; [Aib^(16,34)]hPTH(1-34)NH₂; [Aib^(19,34)]hPTH(1-34)NH₂; [Cha^(7,11)Nle^(8,18), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂; [Cha^(7,11), Nle^(8,18,31), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂; [Cha⁷, Aib¹⁶]hPTH(1-34)NH₂; [Cha¹¹, Aib¹⁶]hPTH(1-34)NH₂; [Cha⁷, Aib³⁴]hPTH(1-34)NH₂; [Cha¹¹, Aib³⁴]hPTH(1-34)NH₂; [Cha²⁷, Aib¹⁶]hPTH(1-34)NH₂; [Cha²⁷, Aib³⁴]hPTH(1-34)NH₂; [Cha²⁸, Aib¹⁶]hPTH(1-34)NH₂; [Cha²⁸, Aib³⁴]hPTH(1-34)NH₂; [Nle³¹]hPTH(1-34)NH₂; [hArg²⁷]hPTH(1-34)NH₂; [Dap¹, Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂; [Nle³¹]bPTH(1-34)NH₂; [Nle³¹]rPTH(1-34)NH₂; [hArg²⁷]bPTH(1-34)NH₂; [hArg²⁷]rPTH(1-34)NH₂; [Cha^(7,11), Aib¹⁹, Lys³⁰]hPTH(1-34)NH₂; [Aib¹²]hPTH(1-34)NH₂; [Cha^(24,28,31), Lys³⁰]hPTH(1-34)NH₂; [Cha^(28,31)]hPTH(1-34)NH₂; [Cha^(7,11), Nle^(8,18), Aib³⁴]hPTH(1-34)NH₂; [Aib³]hPTH(1-34)NH₂; [Cha⁸]hPTH(1-34)NH₂; [Cha¹⁵]hPTH(1-34)NH₂; [Cha^(7,11), Aib¹⁹]hPTH(1-34)NH₂; [Cha^(7,11), Aib¹⁶]hPTH(1-34)NH₂; [Aib¹⁷]hPTH(1-34)NH₂; [Cha⁵]hPTH(1-34)NH₂; [Cha^(7,11,15)]hPTH(1-34)NH₂; [Cha^(7,11), Nle^(8,18), Aib¹⁹, Tyr³⁴]hPTH(1-34)NH₂; [Cha^(7,11), Nle^(8,18), Aib¹⁹, Lys³⁰, Tyr³⁴]hPTH(1-34)NH₂; [Cha^(7,11,15)]hPTH(1-34)NH₂; [Aib¹⁷]hPTH(1-34)NH₂; [Cha^(7,11), Leu²⁷]hPTH(1-34)NH₂; [Cha^(7,11,15), Leu²⁷]hPTH(1-34)NH₂; [Cha^(7,11,27)]hPTH(1-34)NH₂; [Cha^(7,11,15,27)]hPTH(1-34)NH₂; [Trp¹⁵]hPTH(1-34)NH₂; [Nal¹⁵]hPTH(1-34)NH₂; [Trp¹⁵, Cha²³]hPTH(1-34)NH₂; [Cha^(15,23)]hPTH(1-34)NH₂; [Phe^(7,11)]hPTH(1-34)NH₂; [Nal^(7,11)]hPTH(1-34)NH₂; [Trp^(7,11)]hPTH(1-34)NH₂; [Phe^(7,11,15)]hPTH(1-34)NH₂; [Nal^(7,11,15)]hPTH(1-34)NH₂; [Trp^(7,11,15)]hPTH(1-34)NH₂; and [Tyr^(7,11,15)]hPTH(1-34)NH₂.

The following are specific examples of peptides encompassed by one or more of formulas (III) to (V), hereinabove: [Cha⁷]hPTHrP(1-34)NH₂; [Cha¹¹]hPTHrP(1-34)NH₂; [Cha^(7,11)]hPTHrP(1-34)NH₂; [Aib¹⁶, Tyr³⁴hPTHrP(1-34)NH₂; [Aib¹⁹]hPTHrP(1-34)NH₂; [Aib^(16,19)]hPTHrP(1-34)NH₂; [Cha^(7,11), Aib¹⁶hPTHrP(1-34)NH₂; [Cha^(7,11), Aib¹⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu^(25,29), Leu^(28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Lys^(23,26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Cha³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,31), Lys^(26,28,30)]hPTHrP(1-34) NH₂; [Cha^(22,23,24,27,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha^(23,24,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha^(23,24,27,31), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Lys^(23,26,30), Cha^(24,27,28,31)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,31), Glu^(25,29), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Cha²², Lys^(23,26,30), Glu^(25,29), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys^(26,27,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Lys^(23,26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,31), Lys^(26,28,30), Aib²⁹]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,11,22), Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25,29), Leu^(23,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Cha^(7,11,22,23), Glu^(25,29), Leu^(28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25,29), Lys^(23,26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25,29), Leu^(23,31), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,11), Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(15,22), Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Cha^(15,22,23), Glu^(25,29), Leu^(28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,25,29), Lys^(23,26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Cha¹⁵, Glu^(22,28,29), Leu^(23,31), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Cha^(15,30), Glu^(22,25,29), Leu^(23,28,31), Lys²⁶]hPTHrP(1-34)NH₂; [Cha^(7,8,22), Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25,29), Leu^(23,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Cha^(7,8,22,23), Glu^(25,29), Leu^(28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25,29), Lys^(23,26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Cha^(7,8), Glu^(22,25,29), Leu^(23,31), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Cha^(7,8,30), Glu^(22,25,29), Leu^(23,28,31), Lys²⁶]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11,22), Met⁸, Asn¹⁰, His¹⁴, Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25,29), Leu^(23,31), Lys^(26,28,30)]hPTHrP(1-34)NH₂; Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,2,29), Lys^(23,26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Aib³⁰]PTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11,22,23), Met⁸, Asn¹⁰, His¹⁴, Glu^(25,29), Leu^(28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11,15), Met⁸, Asn¹⁰, His¹⁴]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu¹¹, His¹⁴, Aib¹⁶]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,28,31), His¹⁴, Cha^(22,23), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,11), Met⁸, Asn¹⁰, His¹⁴, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, His¹⁴, Cha¹⁵, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Cha^(7,8), Asn¹⁰, His¹⁴, Glu^(22,25,29), Leu^(23,28,31), Lys^(26,30)]hPTHrP(1-34)NH₂; (1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys^(24,26,30)]hPTHrP(1-34)NH₂; [Aib²², Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Aib²⁶, Lys³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28),Lys^(26,30,31)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Cha²², Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,28,31), His¹⁴, Glu^(22,25,29), Lys^(23,26,30)]PTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Glu^(22,25,29), Lys^(26,27,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,31), His¹⁴, Glu^(22,25,29), Lys^(26,28,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Glu^(22,25), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂; [Ser¹, Ile⁵, Met⁸, Asn¹⁰, Leu^(11,23,28,31), His¹⁴, Glu^(22,25,29), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; or [Ser¹, Ile⁵, Met⁸]hPTHrP(1-34)NH₂. [Glu^(22,25), Ahc²³, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25,) Leu^(23,28,31), Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25,) Leu^(23,28), Aib²⁹, Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,25,) Cha²³, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25,) Cha²³, Lys^(26,30), Leu²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib²⁹, Ahc³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25), Cha²³, Lys^(26,30), Aib²⁹, Leu³¹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Ahc²⁴, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,31), Lys^(26,30), Ahc²⁸, Aib²⁹]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Lys²⁶, Aib^(29,30)]hPTHrP(1-34)NH₂; [Aib^(22,29), Leu^(23,28,31), Glu²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28,31), Aib^(26,29), Lys³⁰]hPTHrP(1-34)NH₂; [Cha²², Ahc²³, Glu^(25,29), Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Ahc²⁴, Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; (Cha²², Leu^(23,31), Glu^(25,29), Lys^(26,30), Ahc²⁸]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Leu²⁸, Ahc³⁰]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu^(25,29), Lys^(26,30), Leu³¹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28), Glu^(25,29), Lys^(26,30), Ahc³¹]hPTHrP(114 34)NH₂; [Cha^(22,23), Glu^(25,29), Lys^(26,30), Leu³¹]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu^(25,29), Lys^(26,30), Leu²⁸]hPTHrP(1-34)NH₂; [Cha^(22,23), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu²², Leu^(23,28,31), Aib^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,29), Ahc²³, Aib²⁵, Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Aib²⁵, Lys^(26,30), Glu²⁹]hPTHrP(1-34)NH₂; [Aib^(22,25), Leu^(23,28,31), Lys^(26,30), Glu²⁹]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Ahc²⁴, Aib²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib^(25,26), Lys³⁰]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,31), Aib²⁵, Lys^(26,30), Ahc²⁸]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28), Aib²⁵, Lys^(26,30), Ahc³¹]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib^(25,30), Lys²⁶]hPTHrP(1-34)NH₂; [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂; [Glu^(22,29), Cha²³, Aib²⁵, Lys^(26,30), Leu^(28,31)]hPTHrP(1-34)NH₂; [Glu^(22,29), Cha²³, Aib²⁵, Lys^(26,30), Leu³¹]hPTHrP(1-34)NH₂; [Glu^(22,29), Cha²³, Aib²⁵, Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,29), Cha²³, Aib²⁵, Lys^(26,30), Leu²⁸]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha²³, Lys²⁶, Leu^(28,31), Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha²³, Lys²⁶, Aib³⁰, Leu³¹]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha²³, Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Cha²³, Lys²⁶, Leu²⁸, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Ahc²⁷, Aib³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Ahc²⁴, Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Glu^(25,29), Lys²⁶, Aib³⁰]hPTHrP(1-34)NH₂; [Aib^(22,30), Leu^(23,28,31), Glu^(25,29), Lys²⁶]hPTHrP(1-34)NH₂; [Glu^(22,25), Leu^(23,28), Lys^(26,30,31), Aib²⁹]hPTHrP(1-34)NH₂; [Cha²², Leu^(23,28), Glu^(25,29), Lys^(26,30,31)]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28), Glu^(25,29), Lys^(26,30,31)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28), Lys^(26,30,31), Ahc³⁰]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂; [Ahc²², Leu^(23,28,31), Glu^(25,29), Lys^(26,30)]hPTHrP(1-34)NH₂; [Glu^(22,25,29), Leu^(23,28), Lys^(26,30,31), Ahc²⁷]hPTHrP(1-34)NH₂.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a compound of formula (I), (II), (III), (IV) or (V) or a pharmaceutically acceptable salt thereof, as defined hereinabove.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a combination of a bisphosphonate or calcitonin and a compound of formula (I), (II), (III), (IV) or (V) or a pharmaceutically acceptable salt thereof, as defined hereinabove.

In another aspect, the present invention is directed to a pharmaceutical composition comprising a compound of formula (I), (II), (III), (IV) or (V) or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent.

In another aspect, the present invention is directed to a pharmaceutical composition comprising a compound of formula (I), (II), (Ill), (IV) or (V) or a pharmaceutically acceptable salt thereof as defined hereinabove, a bisphosphonate or calcitonin and a pharmaceutically acceptable carrier or diluent.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a combination of a bisphosphonate or calcitonin and a peptide of the formula [Glu^(22,25), Leu^(2328,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt there

In another aspect, the present invention is directed to a pharmaceutical composition comprising a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent.

In another aspect, the present invention is directed to a pharmaceutical composition comprising a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof, a bisphosphonate or calcitonin, and a pharmaceutically acceptable carrier or diluent.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a peptide of the formula (VI):

wherein

A₁ is Ala, Ser, or Dap;

A₃ is Ser or Aib;

A₅ is His, Ile, Acc, or Cha;

A₇ is Leu, Cha, Nle, β-Nal, Trp, Pal, Acc, Phe, or p-X-Phe in which X is OH, a halogen, or CH₃;

A₈ is Leu, Met, Acc, or Cha;

A₁₀ is Asp or Asn;

A₁₁ is Lys, Leu, Cha, Acc, Phe, or β-Nal;

A₁₂ is Gly, Acc, or Aib;

A₁₄ is Ser or His;

A₁₅ is Ile, Acc, or Cha;

A₁₆ is Gln or Aib;

A₁₇ is Asp or Aib;

A₁₈ is Leu, Aib, Acc, or Cha;

A₁₉ is Arg or Aib;

A₂₂ is Phe, Glu, Aib, Acc, or Cha;

A₂₃ is Phe, Leu, Lys, Acc, or Cha;

A₂₄ is Leu, Lys, Acc, or Cha;

A₂₅ is His, Lys, Aib, Acc, or Glu;

A₂₆ is His, Aib, Acc, or Lys;

A₂₇ is Leu, Lys, Acc, or Cha;

A₂₈ is Ile, Leu, Lys, Acc, or Cha;

A₂₉ is Ala, Glu, Acc, or Aib;

A₃₀ is Glu, Leu, Nle, Cha, Aib, Acc, or Lys;

A₃₁ is Ile, Leu, Cha, Lys, Acc, or deleted;

A₃₂ is His or deleted;

A₃₃ is Thr or deleted;

A₃₄ is Ala or deleted;

each of R₁ and R₂ is, independently, H, C₁₋₁₂ alkanyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂, hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; or one and only one of R₁ and R₂ is COE₁ in which E₁ is C₁₋₁₂ alkyl, C₂₋₁₂ alkyl, C₂₋₁₂ alkenyl, C₇₋₂₀ phenylalkyl, C₁₁₋₂₀ naphthylalkyl, C₁₋₁₂ hydroxyalkyl, C₂₋₁₂ hydroxyalkenyl, C₇₋₂₀ hydroxyphenylalkyl, or C₁₁₋₂₀ hydroxynaphthylalkyl; and

R₃ is OH, NH₂, C₁₋₁₂ alkoxy, or NH—Y—CH₂—Z in which Y is a C₁₋₁₂ hydrocarbon moiety and Z is H, OH, CO₂H or CONH₂;

provided that at least one of A₅, A₇, A₈, A₁₁, A₁₂, A₁₅, A₁₈, A₂₂, A₂₃, A₂₄, A₂₅, A₂₆, A₂₇, A₂₈, A₂₉, A₃₀, or A₃₁ is Acc; or a pharmaceutically acceptable salt thereof.

In another aspect, the present invention is directed to a method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a combination of a bisphosphonate or calcitonin and a peptide of formula (VI), as defined hereinabove.

In another aspect, the present invention is directed to a pharmaceutical composition comprising a pharmaceutically acceptable carrier or diluent and a peptide of formula (VI), as defined hereinabove.

In another aspect, the present invention is directed to a pharmaceutical composition comprising a bisphosphonate or calcitonin, a pharmaceutically acceptable carrier or diluent, and a peptide of formula (VI), as defined hereinabove.

With the exception of the N-terminal amino acid, all abbreviations (e.g. Ala or A₁) of amino acids in this disclosure stand for the structure of —NH—CH(R)—CO—, wherein R is a side chain of an amino acid (e.g., CH₃ for Ala). For the N-terminal amino acid, the abbreviation stands for the structure of ═N—CH(R)—CO—, wherein R is a side chain of an amino acid. β-Nal, Nle, Dap, Cha, Nva, Amp, Pal, Ahc, and Aib are the abbreviations of the following α-amino acids: β-(2-naphthyl)alanine, norleucine, α,β-diaminopropionic acid, cyclohexylalanine, norvaline, 4-amino-phenylalanine, β-(3-pyridinyl)alanine, 1-amino-1-cyclo-hexanecarboxylic acid, and α-aminoisobutyric acid, respectively. What is meant by Acc is an amino acid selected from the group of 1-amino-1-cyclopropanecarboxylic acid; 1-amino-1-cyclobutanecarboxylic acid 1-amino-1-cyclopentanecarboxylic acid; 1-amino-1-cyclohexanecarboxylic acid; 1-amino-1-cycloheptanecarboxylic acid; 1-amino-1-cyclooctanecarboxylic acid; and 1-amino-1-cyclononanecarboxylic acid. In the above formula, hydroxyalkyl, hydroxyphenyl-alkyl, and hydroxynaphthylalkyl may contain 1-4 hydroxy substituents. Also, COE₁ stands for —C═O.E₁. Examples of —C═O.E₁ include, but are not limited to, acetyl and phenylpropionyl.

A peptide of this invention is also denoted herein by another format, e.g., [Acc^(7,11)]hPTH(1-34)NH₂, with the substituted amino acids from the natural sequence placed between the second set of brackets (e.g., Ahc⁷ for Leu⁷, and Ahc¹¹ for Leu¹¹ in hPTH). The abbreviation hPTH stands for human PTH, hPTHrP for human PTHrP, rPTH for rat PTH, and bPTH for bovine PTH. The numbers between the parentheses refer to the number of amino acids present in the peptide (e.g., hPTH(1-34) is amino acids 1 through 34 of the peptide sequence for human PTH). The sequences for hPTH(1-34), hPTHrP(1-34), bPTH(1-34), and rPTH(1-34) are listed in Nissenson, et al., Receptor, 3:193 (1993). The designation “NH₂” in PTH(1-34)NH₂ indicates that the C-terminus of the peptide is amidated. PTH(1-34), on the other hand, has a free acid C-terminus.

Each of the peptides of the invention is capable of stimulating the growth of bone in a subject (i.e., a mammal such as a human patient). Thus, it is useful in the treatment of osteoporosis and bone fractures when administered alone or concurrently with antiresorptive therapy, e.g., bisphosphonates and calcitonin.

The peptides of this invention can be provided in the form of pharmaceutically acceptable salts. Examples of such salts include, but are not limited to, those formed with organic acids (e.g., acetic, lactic, maleic, citric, malic, ascorbic, succinic, benzoic, methanesulfonic, toluenesulfonic, or pamoic acid), inorganic acids (e.g., hydrochloric acid, sulfuric acid, or phosphoric acid), and polymeric acids (e.g., tannic acid, carboxymethyl cellulose, polylactic, polyglycolic, or copolymers of polylactic-glycolic acids).

A therapeutically effective amount of a peptide of this invention and a pharmaceutically acceptable carrier substance (e.g., magnesium carbonate, lactose, or a phospholipid with which the therapeutic compound can form a Michelle) together form a therapeutic composition (e.g., a pill, tablet, capsule, or liquid) for administration (e.g., orally, intravenously, transdermally, pulmonarily, vaginally, subcutaneously, nasally, iontophoretically, or by intratracheally) to a subject. The pill, tablet, or capsule that is to be administered orally can be coated with a substance for protecting the active composition from the gastric acid or intestinal enzymes in the stomach for a period of time sufficient to allow it to pass undigested into the small intestine. The therapeutic composition can also be in the form of a biodegradable or nonbiodegradable sustained release formulation for subcutaneous or intramuscular administration. See, e.g., U.S. Pat. Nos. 3,773,919 and 4,767,628 and PCT Application No. WO 94/15587. Continuous administration can also be achieved using an implantable or external pump (e.g., INFUSAID™ pump). The administration can also be conducted intermittently, e.g., single daily injection, or continuously at a low dose, e.g., sustained release formulation.

The dose of a peptide of the present invention for treating the above-mentioned diseases or disorders varies depending upon the manner of administration, the age and the body weight of the subject, and the condition of the subject to be treated, and ultimately will be decided by the attending physician or veterinarian.

Also contemplated within the scope of this invention is a peptide covered by the above generic formula for use in treating diseases or disorders associated with deficiency in bone growth or the like, e.g., osteoporosis or fractures.

Other features and advantages of the present invention will be apparent from the detailed description and from the claims.

DETAILED DESCRIPTION OF THE INVENTION

Based on the description herein, the present invention can be utilized to its fullest extent. The following specific examples are to be construed as merely illustrative, and should not be construed as a limitation of the remainder of the disclosure in any way whatsoever. Further, all publications cited herein are incorporated by reference.

Structure

PTH(1-34) and PTHrP(1-34) have been reported to have two amphophilic alpha helical domains. See, e.g., Barden, et al., Biochem., 32:7126 (1992). The first ″-helix is formed between amino acid residues 4 through 13, while the second ″-helix is formed between amino acid residues 21 through 29. Some peptides of this invention contain the substitution of Acc for one or more residues within or near these two regions of PTH(1-34) and PTHrP(1-34), e.g., Ahc⁷ and Ahc¹¹ within the first ″-helix or Ahc²⁷ and Ahc²⁸ within the second ″-helix; or Cha⁷ and Cha¹¹ within the first α-helix or Cha²⁷ and Cha²⁸ within the second α-helix.

Synthesis

The peptides of the invention can be prepared by standard solid phase synthesis. See, e.g., Stewart, J. M., et al., Solid Phase Synthesis (Pierce Chemical Co., 2d ed. 1984). The following is a description of how [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTH(1-34)NH₂ was prepared. Other peptides of the invention can be prepared in an analogous manner by a person of ordinary skill in the art.

1-[N-tert-Butoxycarbonyl-amino]-1-cyclohexane-carboxylic acid(Boc-Ahc-OH) was synthesized as follows:

19.1 g (0.133 mol) of 1-amino-1-cyclohexanecarboxylic acid (Acros Organics, Fisher Scientific, Pittsburgh, Pa.) was dissolved in 200 ml of dioxane and 100 ml of water. To it was added 67 mg of 2N NaOH. The solution was cooled in an ice-water bath. 32.0 g (0.147 mol) of di-tert-butyl-dicarbonate was added to this solution. The reaction mixture was stirred overnight at room temperature. Dioxane was then removed under reduced pressure. 200 ml of ethyl acetate was added to the remaining aqueous solution. The mixture was cooled in an ice-water bath. The pH of the aqueous layer was adjusted to about 3 by adding 4N HCl. The organic layer was separated. The aqueous layer was extracted with ethyl acetate (1×100 ml). Two organic layers were combined and washed with water (2×150 ml), dried over anhydrous MgSO₄, filtered, and concentrated to dryness under reduced pressure. The residue was recrystallized in ethyl acetate/hexanes. 9.2 g of a pure product was obtained. 29% yield. Other protected Acc amino acids can be prepared in an analogous manner by a person or ordinary skill in the art.

The peptide was synthesized on an Applied Biosystems (Foster City, Calif.) model 430A peptide synthesizer which was modified to do accelerated Boc-chemistry solid phase peptide synthesis. See Schnoize, et al., Int. J. Peptide Protein Res., 90:180 (1992). 4-Methylbenz-hydrylamine (MBHA) resin (Peninsula, Belmont, Calif.) with the substitution of 0.93 mmol/g was used. The Boc amino acids (Bachem, CA, Torrance, Calif.; Nova Biochem., LaJolla, Calif.) were used with the following side chain protection: Boc-Ala-OH, Boc-Arg(Tos)-OH, Boc-Asp(OcHex)-OH, Boc-Glu(OcHex)-OH, Boc-His(DNP)-OH, Boc-Val-OH, Boc-Leu-OH, Boc-Gly-OH, Boc-Gln-OH, Boc-Ile-OH, Boc-Lys(2ClZ)-OH, Boc-Acc-OH, Boc-Thr(Bzl)-OH, Boc-Ser(Bzl)-OH; and Boc-Aib-OH. The synthesis was carried out on a 0.14 mmol scale. The Boc groups were removed by treatment with 100% TFA for 2×1 min. Boc amino acids (2.5 mmol) were pre-activated with HBTU (2.0 mmol) and DIEA (1.0 mL) in 4 mL of DMF and were coupled without prior neutralization of the peptide-resin TFA salt. Coupling times were 5 min except for the Boc-Aib-OH, and its following residue Boc-Leu-OH, and Boc-Ahc-OH, and its following residue Boc-Lys(2Clz)-OH, wherein the coupling times for these four residues were 2 hrs.

At the end of the assembly of the peptide chain, the resin was treated with a solution of 20% mercaptoethanol/10% DIEA in DMF for 2×30 min. to remove the DNP group on the His side chain. The N-terminal Boc group was then removed by treatment with 100% TFA for 2×2 min. The partially-deprotected peptide-resin was washed with DMF and DCM and dried under reduced pressure. The final cleavage was done by stirring the peptide-resin in 10 mL of HF containing 1 mL of anisole and dithiothreitol (24 mg) at 0EC for 75 min. HF was removed by a flow of nitrogen. The residue was washed with ether (6×10 mL) and extracted with 4N HOAc (6×10 mL).

The peptide mixture in the aqueous extract was purified on a reversed-phase preparative high pressure liquid chromatography (HPLC) using a reversed phase VYDAC™ C₁₈ column (Nest Group, Southborough, Mass.). The column was eluted with a linear gradient (10% to 45% of solution B over 130 min.) at a flow rate of 10 mL/min (Solution A=0.1% aqueous TFA; Solution B=acetonitrile containing 0.1% of TFA). Fractions were collected and checked on analytical HPLC. Those containing pure product were combined and lyophilized to dryness. 85 mg of a white solid was obtained. Purity was >99% based on analytical HPLC analysis. Electro-spray mass spectrometer analysis gave the molecular weight at 3972.4 (in agreement with the calculated molecular weight of 3972.7).

The synthesis and purification of [Cha²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂ was carried out in the same manner as the above synthesis of [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTHrP(1-34)NH₂. The protected amino acid Boc-Cha-OH was purchased from Bachem, CA. The purity of the final product was >99%, and the electron-spray mass spectrometer gave the molecular weight at 3997.2 (calculated molecular weight is 3996.8).

The following is a description of how [Aib³⁴]hPTH(1-34)NH₂ was prepared. The peptide, [Aib³⁴]hPTH(1-34)NH₂, was synthesized on an Applied Biosystems (Foster City, Calif.) model 430A peptide synthesizer which was modified to do accelerated Boc-chemistry solid phase peptide synthesis. See Schnoize, et al., Int. J. Peptide Protein Res., 90:180 (1992). 4-Methylbenz-hydrylamine (MBHA) resin (Peninsula, Belmont, Calif.) with the substitution of 0.93 mmol/g was used. The Boc amino acids (Bachem, CA, Torrance, Calif.; Nova Biochem., LaJolla, Calif.) were used with the following side chain protection: Boc-Arg(Tos)-OH, Boc-Asp(OcHxl)-OH, Boc-Asn(Xan)-OH, Boc-Glu(OcHxl)-OH, Boc-His(DNP)-OH, Boc-Asn-GH, Boc-Val-OH, Boc-Leu-OH, Boc-Ser-OH, Boc-Gly-OH, Boc-Met-OH, Boc-Gln-OH, Boc-Ile-OH, Boc-Lys(2ClZ)-OH, Boc-Ser(Bzl)-OH, and Boc-Trp(Fm)-OH. The synthesis was carried out on a 0.14 mmol scale. The Boc groups were removed by treatment with 100% TFA for 2×1 min. Boc amino acids (2.5 mmol) were pre-activated with HBTU (2.0 mmol) and DIEA (1.0 mL) in 4 mL of DMF and were coupled without prior neutralization of the peptide-resin TFA salt. Coupling times were 5 min except for the Boc-Aib-OH and the following residue, Boc-Asn(Xan)-OH, wherein the coupling times were 20 min.

At the end of the assembly of the peptide chain, the resin was treated with a solution of 20% mercaptoethanol/10% DIEA in DMF for 2×30 min. to remove the DNP group on the His side chain. The N-terminal Boc group was then removed by treatment with 100% TFA for 2×2 min. After neutralization of the peptide-resin with 10% DIEA in DMF (1×1 min.), the formyl group on the side chain of Trp was removed by treatment with a solution of 15% ethanolamine/15% water/70% DMF for 2×30 min. The partially-deprotected peptide-resin was washed with DMF and DCM and dried under reduced pressure. The final cleavage was done by stirring the peptide-resin in 10 mL of HF containing 1 mL of anisole at 0° C. for 75 min. HF was removed by a flow of nitrogen. The residue was washed with ether (6×10 mL) and extracted with 4N HOAc (6×10 mL).

The peptide mixture in the aqueous extract was purified on a reversed-phase preparative high pressure liquid chromatography (HPLC) using a reversed phase VYDAC™ C₁₈ column (Nest Group, Southborough, Mass.). The column was eluted with a linear gradient (10% to 45% of solution B over 130 min.) at a flow rate of 10 mL/min (Solution A=0.1% aqueous TFA; Solution B=acetonitrile containing 0.1% of TFA). Fractions were collected and checked on analytical HPLC. Those containing pure product were combined and lyophilized to dryness. 62.3 mg of a white solid was obtained. Purity was >99% based on analytical HPLC analysis. Electro-spray mass spectrometer analysis gave the molecular weight at 4054.7 (in agreement with the calculated molecular weight of 4054.7).

The synthesis and purification of [Cha^(7,11)]hPTH(1-34)NH₂ was carried out in the same manner as the above synthesis of [Aib³⁴]hPTH(1-34)NH₂. The protected amino acid Boc-Cha-OH was purchased from Bachem, CA. The purity of the final product was >98%, and the electron-spray mass spectrometer gave the molecular weight at 4197.0 (calculated molecular weight is 4196.9).

The following is a description of how [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTH(1-34)NH₂ was prepared. Other peptides of the invention can be prepared in an analogous manner by a person of ordinary skill in the art.

1-[N-tert-Butoxycarbonyl-amino]-1-cyclohexane-carboxylic acid (Boc-Ahc-OH) was synthesized as follows:

19.1 g (0.133 mol) of 1-amino-1-cyclohexanecarboxylic acid (Acros Organics, Fisher Scientific, Pittsburgh, Pa.) was dissolved in 200 ml of dioxane and 100 ml of water. To it was added 67 mg of 2N NaOH. The solution was cooled in an ice-water bath. 32.0 g (0.147 mol) of di-tert-butyl-dicarbonate was added to this solution. The reaction mixture was stirred overnight at room temperature. Dioxane was then removed under reduced pressure. 200 ml of ethyl acetate was added to the remaining aqueous solution. The mixture was cooled in an ice-water bath. The pH of the aqueous layer was adjusted to about 3 by adding 4N HCl. The organic layer was separated. The aqueous layer was extracted with ethyl acetate (1×100 ml). Two organic layers were combined and washed with water (2×150 ml), dried over anhydrous MgSO₄, filtered, and concentrated to dryness under reduced pressure. The residue was recrystallized in ethyl acetate/hexanes. 9.2 g of a pure product was obtained. 29% yield. Other protected Acc amino acids can be prepared in an analogous manner by a person or ordinary skill in the art.

The peptide was synthesized on an Applied Biosystems (Foster City, Calif.) model 430A peptide synthesizer which was modified to do accelerated Boc-chemistry solid phase peptide synthesis. See Schnoize, et al., Int. J. Peptide Protein Res., 90:180 (1992). 4-Methylbenz-hydrylamine (MBHA) resin (Peninsula, Belmont, Calif.) with the substitution of 0.93 mmol/g was used. The Boc amino acids (Bachem, CA, Torrance, Calif.; Nova Biochem., LaJolla, Calif.) were used with the following side chain protection: Boc-Ala-OH, Boc-Arg(Tos)-OH, Boc-Asp(OcHex)-OH, Boc-Glu(OcHex)-OH, Boc-His(DNP)-OH, Boc-Val-OH, Boc-Leu-OH, Boc-Gly-OH, Boc-Gln-OH, Boc-Ile-OH, Boc-Lys(2ClZ)-OH, Boc-Acc-OH, Boc-Thr(Bzl)-OH, Boc-Ser(Bzl)-OH; and Boc-Aib-OH. The synthesis was carried out on a 0.14 mmol scale. The Boc groups were removed by treatment with 100% TFA for 2×1 min. Boc amino acids (2.5 mmol) were pre-activated with HBTU (2.0 mmol) and DIEA (1.0 mL) in 4 mL of DMF and were coupled without prior neutralization of the peptide-resin TFA salt. Coupling times were 5 min except for the Boc-Aib-OH, and its following residue Boc-Leu-OH, and Boc-Ahc-OH, and its following residue Boc-Lys(2Clz)-OH, wherein the coupling times for these four residues were 2 hrs.

At the end of the assembly of the peptide chain, the resin was treated with a solution of 20% mercaptoethanol/10% DIEA in DMF for 2×30 min. to remove the DNP group on the His side chain. The N-terminal Boc group was then removed by treatment with 100% TFA for 2×2 min. The partially-deprotected peptide-resin was washed with DMF and DCM and dried under reduced pressure. The final cleavage was done by stirring the peptide-resin in 10 mL of HF containing 1 mL of anisole and dithiothreitol (24 mg) at 0° C. for 75 min. HF was removed by a flow of nitrogen. The residue was washed with ether (6×10 mL) and extracted with 4N HOAc (6×10 mL).

The peptide mixture in the aqueous extract was purified on a reversed-phase preparative high pressure liquid chromatography (HPLC) using a reversed phase VYDAC™ C₁₈ column (Nest Group, Southborough, Mass.). The column was eluted with a linear gradient (10% to 45% of solution B over 130 min.) at a flow rate of 10 mL/min (Solution A=0.1% aqueous TFA; Solution B=acetonitrile containing 0.1% of TFA). Fractions were collected and checked on analytical HPLC. Those containing pure product were combined and lyophilized to dryness. 85 mg of a white solid was obtained. Purity was >99% based on analytical HPLC analysis. Electro-spray mass spectrometer analysis gave the molecular weight at 3972.4 (in agreement with the calculated molecular weight of 3972.7).

The synthesis and purification of [Cha²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂ was carried out in the same manner as the above synthesis of [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTHrP(1-34)NH₂. The protected amino acid Boc-Cha-OH was purchased from Bachem, CA. The purity of the final product was >99%, and the electron-spray mass spectrometer gave the molecular weight at 3997.2 (calculated molecular weight is 3996.8).

The full names for the abbreviations used above are as follows: Boc for t-butyloxycarbonyl, HF for hydrogen fluoride, Fm for formyl, Xan for xanthyl, Bzl for benzyl, Tos for tosyl, DNP for 2,4-dinitrophenyl, DMF for dimethylformamide, DCM for dichloromethane, HBTU for 2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyl uronium hexafluorophosphate, DIEA for diisopropylethylamine, HOAc for acetic acid, TFA for trifluoroacetic acid, 2ClZ for 2-chlorobenzyloxycarbonyl, and OcHex for O-cyclohexyl.

The substituents R₁ and R₂ of the above generic formula may be attached to the free amine of the N-terminal amino acid by standard methods known in the art. For example, alkyl groups, e.g., C₁₋₁₂ alkyl, may be attached using reductive alkylation. Hydroxyalkyl groups, e.g., C₁₋₁₂ hydroxyalkyl, may also be attached using reductive alkylation wherein the free hydroxy group is protected with a t-butyl ester. Acyl groups, e.g., COE₁, may be attached by coupling the free acid, e.g., E₁COOH, to the free amine of the N-terminal amino acid by mixing the completed resin with 3 molar equivalents of both the free acid and diisopropylcarbodiimide in methylene chloride for one hour and cycling the resulting resin through steps (a) to (f) in the above wash program. If the free acid contains a free hydroxy group, e.g., p-hydroxyphenylpropionic acid, then the coupling should be performed with an additional 3 molar equivalents of HOBT.

Other peptides of this invention can be prepared in an analogous manner by a person of ordinary skill in the art.

Functional Assays

A. Binding to PTH Receptor

The peptides of the invention were tested for their ability to bind to the PTH receptor present on SaOS-2 (human osteosarcoma cells). SaOS-2 cells (American Type Culture Collection, Rockville, Md.; ATCC #HTB 85) were maintained in RPMI 1640 medium (Sigma, St. Louis, Mo.) supplemented with 10% fetal bovine serum (FBS) and 2 mM glutamine at 37EC in a humidified atmosphere of 5% CO₂ in air. The medium was changed every three or four days, and the cells were subcultured every week by trypsinization.

SaOS-2 cells were maintained for four days until they had reached confluence. The medium was replaced with 5% FBS in RPMI 1640 medium and incubated for 2 hrs at room temperature with 10×10⁴ cpm mono-¹²⁵I-[Nle^(8,18), Tyr³⁴(3-¹²⁵I)]bPTH(1-34)NH₂ in the presence of a competing peptides of the invention at various concentrations between 10⁻¹¹M to 10⁻⁴ M. The cells were washed four times with ice-cold PBS and lysed with 0.1 M NaOH, and the radioactivity associated with the cells was counted in a scintillation counter. Synthesis of mono-¹²⁵I-[Nle^(8,18), Tyr³⁴(3-¹²⁵I)]bPTH(1-34)NH₂ was carried out as described in Goldman, M. E., et al., Endocrinol., 123:1468 (1988).

The binding assay was conducted with various peptides of the invention, and the Kd value (half maximal inhibition of binding of mono-¹²⁵I-[Nle^(8,18), Tyr³⁴(3-¹²⁵I)]bPTH(1-34)NH₂) for each peptide was calculated.

As shown in Table I, all of the tested peptides had a high binding affinity for the PTH receptor on the SaOS-2 cell.

B. Stimulation of Adenylate Cyclase Activity

The ability of the peptides of the invention to induce a biological response in SaOS-2 cells were measured. More specifically, any stimulation of the adenylate cyclase was determined by measuring the level of synthesis of cAMP (adenosine 3′,5′-monophosphate) as described previously in Rodan, et al., J. Clin. Invest. 72: 1511 (1983) and Goldman, et al., Endocrinol., 123:1468 (1988). Confluent SAOS-2 cells in 24 wells plates were incubated with 0.5:Ci [³H]adenine (26.9 Ci/mmol, New England Nuclear, Boston, Mass.) in fresh medium at 37EC for 2 hrs, and washed twice with Hank's balanced salt solution (Gibco, Gaithersburg, Md.). The cells were treated with 1 mM IBMX [isobutylmethyl-xanthine, Sigma, St. Louis, Mo.] in fresh medium for 15 min, and the peptides of the invention were added to the medium to incubate for 5 min. The reaction was stopped by the addition of 1.2 M trichloroacetic acid (TCA) (Sigma, St. Louis, Mo.) followed by sample neutralization with 4N KOH. cAMP was isolated by the two-column chromatographic method (Salmon, et al., 1974, Anal. Biochem. 58, 541). The radioactivity was counted in a scintillation counter (Liquid Scintillation Counter 2200CA, PACKARD, Downers Grove, Ill.).

The respective EC₅₀ values (half maximal stimulation of adenylate cyclase) for the tested peptides were calculated and shown in Table I. All tested peptides were found to be potent stimulators of adenylate cyclase activity, which is a biochemical pathway indicative as a proximal signal for osteoblast proliferation (e.g., bone growth).

TABLE I PEPTIDE Kd (μM) EC₅₀ (nM) [Cha^(7,11)]hPTH(1-34)NH₂ 0.01 0.6 [Cha²³]hPTH(1-34)NH₂ 0.2 20 [Cha²⁴]hPTH(1-34)NH₂ 0.1 10 [Nle^(8,18), Cha²⁷]hPTH(1-34)NH₂; 0.05 2 [Cha²⁸]hPTH(1-34)NH₂ 0.05 2.5 [Cha³¹]hPTH(1-34)NH₂ 0.03 4 [Aib¹⁶]hPTH(1-34)NH₂; 0.004 0.7 [Aib¹⁹]hPTH(1-34)NH₂; 0.005 0.6 [Aib³⁴]hPTH(1-34)NH₂; 0.007 3 [Nle³¹]hPTH(1-34)NH₂; 0.004 0.7 [hArg²⁷]hPTH(1-34)NH₂ 0.007 1 [Dap, Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂ 0.150 10 [Cha^(24,28,31), Lys³⁰]hPTH(1-34)NH₂; 0.5 7 [Cha^(7,11), Nle^(8,18), Tyr³⁴]hPTH(1-34)NH₂ 0.006 0.6 [Cha^(7,11), Nle^(8,18), Aib^(16,19), Tyr³⁴]hPTH(1-34)NH₂ 0.005 1.5 [Cha^(7,11), Nle^(8,18,31), Aib^(16,19), Tyr³⁴]hPTH(1-34) 0.04 4 NH₂ [Cha¹¹]hPTH(1-34)NH₂ 0.005 2 [Cha^(28,31)]hPTH(1-34)NH₂ 0.06 7 [Cha^(7,11), Nle^(8,18), Aib³⁴]hPTH(1-34)NH₂ 0.03 1.5 [Cha¹⁵]hPTH(1-34)NH₂ 0.005 1.3 [Cha^(7,11), Aib¹⁹]hPTH(1-34)NH₂ 0.007 0.5 [Cha^(7,11), Aib¹⁶]hPTH(1-34)NH₂ 0.004 1.1 [Aib^(16,19)]hPTH(1-34)NH₂ 0.004 0.6 [Aib¹²]hPTH(1-34)NH₂ 0.005 2 [Aib³]hPTH(1-34)NH₂ 0.004 1.1 [Cha^(7,11), Aib¹⁹, Lys³⁰]hPTH(1-34)NH₂ 0.004 2 [Cha⁷]hPTH(1-34)NH₂ 0.02 2.3 [Cha^(24,28,31)]hPTH(1-34)NH₂ 1.0 30 [Aib¹⁷]hPTH(1-34) 0.05 3 [Cha^(7,11,15)]hPTH(1-34) 0.01 1.4

TABLE II PEPTIDE Kd (μM) EC₅₀ (nM) [Glu^(22,25), Leu^(23,28), Lys^(26,30), Aib²⁹, Ahc³¹]hPTHrP(1-34)NH₂ 0.200 3.7 [Glu^(22,25), Ahc²³, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂ 0.070 3.9 [Glu^(22,25), Leu^(23,28,31), Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34)NH₂ 0.230 3.0 [Glu^(22,25,29), Leu^(23,28,31), Lys²⁶, Ahc³⁰]hPTHrP(1-34)NH₂ 0.230 20 [Cha²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Ahc²⁷, Aib²⁹]hPTHrP(1-34) 0.060 2.0 NH₂ [Glu^(22,25), Leu^(23,28,31), Ahc²⁴, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂ 0.006 0.5 [Glu^(22,29), Leu^(23,28,31), Aib²⁵, Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂ 5 [Glu²², Leu^(23,28,31), Aib^(25,29), Lys^(26,30), Ahc²⁷]hPTHrP(1-34)NH₂ 2 [Ahe²², Leu^(23,28,31), Glu²⁵, Lys^(26,30), Aib²⁹]hPTHrP(1-34)NH₂ 0.3 [Glu^(22,25), Leu^(23,31), Lys^(26,30), Ahe²⁸, Aib²⁹]hPTHrP(1-34)NH₂ 0.5 [Cha²², Ahc²³, Glu²⁵, Lys^(26,30), Leu^(28,31), Aib²⁹]hPTHrP(1-34)NH₂ 0.4

OTHER EMBODIMENTS

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, that the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the claims.

5 1 34 PRT Artificial Sequence Description of Artificial Sequence Formula Peptide 1 Xaa Val Xaa Glu Xaa Gln Xaa Xaa His Asn Xaa Xaa Lys His Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Arg Xaa Xaa Xaa Xaa Arg Lys Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa 2 34 PRT Artificial Sequence Description of Artificial Sequence Formula Peptide 2 Xaa Val Xaa Glu Xaa Gln Xaa Xaa His Asn Xaa Xaa Lys His Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Arg Xaa Glu Xaa Xaa Arg Lys Xaa Xaa Gln Xaa Xaa Xaa 20 25 30 Xaa Xaa 3 34 PRT Artificial Sequence Description of Artificial Sequence Formula Peptide 3 Xaa Val Xaa Glu Xaa Gln Xaa Xaa His Xaa Xaa Xaa Lys Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Arg Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa 4 34 PRT Artificial Sequence Description of Artificial Sequence Formula Peptide 4 Xaa Val Xaa Glu Xaa Gln Xaa Xaa His Xaa Xaa Xaa Lys Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Arg Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa 5 34 PRT Artificial Sequence Description of Artificial Sequence Formula Peptide 5 Xaa Val Xaa Glu Xaa Gln Xaa Xaa His Xaa Xaa Xaa Lys Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Arg Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa 

What is claimed is:
 1. A method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof.
 2. A method of treating osteoporosis in a patient in need thereof, which comprises administering to said patient a combination of a bisphosphonate or calcitonin and a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof.
 3. A pharmaceutical composition comprising a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier or diluent.
 4. A pharmaceutical composition comprising a peptide of the formula [Glu^(22,25), Leu^(23,28,31), Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂ or a pharmaceutically acceptable salt thereof, a bisphosphonate or calcitonin, and a pharmaceutically acceptable carrier or diluent. 